From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Generics vs. O-O?
Date: Fri, 2 Aug 2013 18:15:47 +0200
Date: 2013-08-02T18:15:47+02:00 [thread overview]
Message-ID: <16h8mgh7dbnqw$.13wra2b10eaya$.dlg@40tude.net> (raw)
In-Reply-To: 8bef1dc4-547b-478e-b81a-09077212f821@googlegroups.com
On Fri, 2 Aug 2013 08:08:38 -0700 (PDT), Shark8 wrote:
> On Friday, August 2, 2013 8:09:46 AM UTC-6, Dmitry A. Kazakov wrote:
>>
>>> For example, if
>>> you'd want a callback to be passed somewhere. Then, dismissing generics
>>> might entail the introduction of one level of indirection (subprogram
>>> pointer),
>>
>> There is no need in using pointers in order to achieve downward closures.
>> It was a kludge of Ada 95 design. Generics is a kludge of Ada 83 design.
>
> No, it was a well thought-out and justified feature; see the Ada83 rationale:
Generics were fashionable back in 80's. We are 30 years older and hopefully
wiser.
>> Yet another language design
>> problem that there is no simple way to declare such singleton types in Ada.
>
> Really?
[...]
> Type K sure looks like a singleton to me.
I mean singleton types vs. closures. It is
type Visitor_Interface is limited interface;
procedure Meet (State : in out Visitor_Interface; Item : Element'Class)
is abstract;
procedure Enumerate
( Collection : Container;
Visitor : in out Visitor_Interface'Class);
vs.
procedure Enumerate
( Collection : Container;
Action : not null access procedure (Item : Element'Class);
There is no need to be it really a singleton either for the object or for
the closure. Just it is the most common case in practice.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2013-08-02 16:15 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-01 14:45 Generics vs. O-O? Eryndlia Mavourneen
2013-08-01 19:24 ` Dmitry A. Kazakov
2013-08-01 19:52 ` Eryndlia Mavourneen
2013-08-01 20:14 ` sbelmont700
2013-08-01 23:35 ` Yannick Duchêne (Hibou57)
2013-08-01 20:10 ` optikos
2013-08-01 20:26 ` Dmitry A. Kazakov
2013-08-01 20:35 ` Jeffrey Carter
2013-08-01 21:22 ` Bill Findlay
2013-08-01 23:38 ` Yannick Duchêne (Hibou57)
2013-08-01 22:20 ` Georg Bauhaus
2013-08-02 8:11 ` Dmitry A. Kazakov
2013-08-02 9:50 ` Georg Bauhaus
2013-08-02 14:09 ` Dmitry A. Kazakov
2013-08-02 15:08 ` Shark8
2013-08-02 15:36 ` Alan Jump
2013-08-02 17:00 ` Jeffrey Carter
2013-08-02 17:51 ` Dmitry A. Kazakov
2013-08-02 18:06 ` Alan Jump
2013-08-02 19:08 ` Dmitry A. Kazakov
2013-08-02 16:15 ` Dmitry A. Kazakov [this message]
2013-08-03 0:04 ` Yannick Duchêne (Hibou57)
2013-08-03 7:35 ` Georg Bauhaus
2013-08-03 8:57 ` Dmitry A. Kazakov
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